Know Your Enemy
by Alexandra Spar
Summary: My first Zim fic. Much sappyness and some mild Zim-Gaz stuff; Zim and Dib find out what REALLY happens when Irken and Human pathogens collide.


The clouds that had soaked most of Earth for almost a week were finally breaking up, thinning and tearing like layers of veils across the sky

This is my first Zim fic, and Gaz at least is WAY out of character, but hey, it's my story and I control...stuff....like that. Yes. Anyway, nothing to do with IZ is mine, it all belongs to Jhonen Vasquez, who is a god among men. All hail Jhonen!!! Please don't sue your humble supplicants.

The clouds that had soaked most of Earth for almost a week were finally breaking up, thinning and tearing like layers of veils across the sky. A weak and watery sunlight fell through the rents in the clouds, illuminating a sodden cityscape fretted with puddles and soggy debris.

Down below, in the suburban streets, a blind was twitched aside and a gleaming red eye regarded the sky with suspicion. "Gir!"

The little robot jumped off the couch and bounded onto the top of Zim's head, chirping brainlessly. Zim shook him off and held him up so he could glare directly into the S.I.R's vacant blue optics. "Gir, listen to me. This is important. The evil human rain has stopped, so I'm going to skool. I need you to keep an eye on the laser weasel experiment."

Gir's eyes flickered red for a moment and he ripped off a smart salute. "Yes, my Master!!"

Zim set him down. "Very well. If you screw up my laser weasels, I'll use your head for boiling spinach in. Got that?"

Gir shuddered. Zim had finally found a food the robot wasn't in love with. "Not the spinach, Master! Please, not the spinach!"

Zim smiled unpleasantly, and left. All around him the world sparkled with hideous danger; agony lurked in each puddle, each droplet glittering in the newfound sun. However, since the water balloon incident, he had refined the paste formula he used as water-block; he had spent much of the monsoon week nervously bathing in paste, and he felt fairly safe even this close to so much water. He did feel strangely weak, though. Must be the lack of exercise.

As he had expected, Dib was waiting for him outside skool, wearing that insufferably smug expression Zim had grown to loathe. "Feeling safe now the big bad raindrops are gone, _Zim_? You've been hiding out in your house all week, haven't you, you extraterrestrial coward?" He sneezed. Zim hadn't known it was possible to sneeze smugly, but Dib seemed to have it down. He regarded the human without love, arching one eyebrow. "As a matter of fact, no, _Dib_. I have spent the past week, ah, with my loving family, observing a religious holiday."

Dib snorted. "Religious holiday? That's the best you can come up with? Jeez, Zim, you're losing your touch."

"I'll thank you not to insult my religion," said Zim with customary hauteur, sweeping past his nemesis and into the skool building. Dib laughed nastily after him, but the laughter became a coughing fit, and he had to hurry to get to class, gasping, before the bell rang. He must've caught the cold everyone seemed to be coming down with. He had time to wonder, once he'd slid into his seat, whether Zim would catch it, and what might happen if he did. 

_Heh_, he thought. _Maybe he really is allergic to human germs. Might make him explode._

The thought warmed him. It seemed like most of the class was sick; there was a general background chorus of coughing and sniffling. _Only a matter of time,_ thought Dib, his toes wiggling with malice. _Only a matter of time before you are defeated by our human pathogens! So much for your superior alien technology!_

He grinned across the class at Zim, who was staring absently into the distance, violet eyes vague. Even the coughing fits that shook Dib couldn't knock that grin off his face; there was finally an intimation that justice would prevail and Earth be preserved from the peril of Zim!

Gaz found him at lunch. By then Dib was not feeling good at all, and the stench of Wednesday's ketchup and rice wasn't helping. He sat off to one side, hunched over a glass of water, shivering. The grin was still there, however; Zim had left class during recess and had not returned, so Dib thought the chances were good that he'd come down with whatever everyone else had. He was thinking happily about this when Gaz sat down beside him, engrossed as always in her Gameslave. 

"Gaz!" he croaked. "I think Zim's finally defeated!"

"Sure, whatever," she muttered. "—Got you, you bastard! Only one more boss and I've beaten the game!"

"Didn't you hear me? I said Zim's defeated! Earth might be safe!"

"Not from you, you weirdo," said Gaz automatically. "Don't bother me now."

Dib felt like shaking her, but he knew it would bring instant and painful retribution. There was nothing he could do to get through to her until she'd finished the game. He took a sip of water, wincing as it burned in his raw throat. Minutes went by.

"Hah! Finally!" Gaz destroyed the last twitching enemy on her little screen, and looked up. "What were you yapping about now?"

"I said," said Dib wearily, "I think there's a good chance Zim has been defeated. Not by any team of paranormal investigators. Oh, no. By germs! Little wiggly germs! Heh heh heh..." He broke off, coughing. Gaz regarded him sourly.

"Don't you mean _you_'ve been defeated by germs?"

"What? No! I have a superior human immune system! This is my planet! My germs!"

"You're starting to talk like him," Gaz said, disgusted. "Get your germs away from me."

"You'll see," muttered Dib hoarsely. "Oh, yes, you'll see the power of the germs. When they have destroyed Zim and his evil, you too will bow down to the....oh, crap. I _am_ starting to talk like him. I'm going to the nurse."

Zim leaned heavily on the inside of his door. So cold suddenly. The thick Earth atmosphere seemed to catch in his chest. He had never felt like this before, and was frightened. 

It had begun in class. All the Earthinoid children around him had been sneezing and coughing, but he'd been too engrossed in his latest plan for world domination to pay any attention to them. He had felt oddly weak all day, and now the weakness seemed to spread and grow, making his head ache and his squigglyspooch churn queasily. For a moment or two he had thought something had poisoned him, but as he coughed to clear the sudden itch in his throat, he realized what it was.

Germs.

He had been _right_ ! They were dangerous. And now they had him.

He had to get back to the safety of his base before his mission was jeopardized any further. 

As soon as he could, Zim escaped the skool, coughing almost continually now. The movements made his head ache more fiercely, and he was starting to feel dizzy and sick. Hurrying home, his mind was racing. What could he do to stop the germs? Irken physiology had never encountered Earth germs before, at least not ones this virulent. He had to report to the Almighty Tallest. To warn them.

Gir was nowhere to be seen. Zim wondered vaguely where the bot had gone, but he had other things to think about. Hurrying to the underground lab, he initiated a transmission to the Tallests' ship.

Red and Purple were enjoying a good old-fashioned game of foosball when the call came in. "Crap," said Red, "it's from Earth."

"No, not Zim again? Man, I'm so sick of him...."

On the screen, a familiar image formed. "What the...." said Red, his antennae wiggling.

Zim was almost white, so pale his skin was only just discernibly green. In the dim light of the lab's equipment, the sweat on his face and throat gleamed dully. His antennae drooped exhaustedly over his face; his great red eyes were half-closed and ringed with shadows. "Zim, you look awful," said Purple, fascinated. At the sound of his leader's voice, Zim jerked and began to cough, muffling it behind a gloved fist. 

At length the spasm ceased. "Excuse me, my Tallests," gasped Zim. "I have an urgent report.....the Earthinoid germs have attacked me.....I'm fighting back, but I don't know how long I can hold out. Beware the germs, my Tallests!" He broke down coughing again. Purple looked at Red, who bit his lip and looked back at Purple.

"Saves us a lot of trouble," Red shrugged.

"Oh, man, just look at him! He's dying!"

"Like I said."

"Oh. Right." Purple glared at his co-ruler. "He's annoying and all, and I have to admit he did destroy most of a hemisphere, but you can't just leave him like that!"

Red scowled at Purple. He had to distract him somehow. "Look!" he cried, pointing dramatically over Purple's shoulder. "Curly fries!!"

"Oooh! Where? Where?"

When they turned back to the screen, all they saw was the white-on-black _Terminated_ sigil.

Zim had sent his message. The strength that had got him home was mostly gone now, and it took all he had to climb back into the elevator to the main house. He was far too hot, now, remembering how he had shivered just a few minutes before. Crawling up the stairs to his room, he collapsed on the bed, coughing uncontrollably. He could not remember ever having felt this sick.

After a while the world receded, and he slept.

Professor Membrane swept along the corridors of the hospital, drawing admiring stares from fan after fan. The girl who followed him, clutching a Gameslave in one hand, noticed none of it. If her suspicions were correct.....

Her father opened the door to Dib's room. He lay paler than usual in the high white bed, his hair disarranged from its normal scythe, his eyes closed. Banks of monitors recorded his vital signs. 

"What's this about a new disease?" the Professor demanded of the doctor who had accompanied them. "How have I not heard of it?"

"It's very, uh, new, Professor. Um." Gaz ignored the adults. Whipping out a tiny syringe, she jabbed it into an untouched area on Dib's arm and drew a blood sample. If she was right...... But she needed Zim's blood as well to find that out.

"I'm going home, Dad," she said as she hurried out. The Professor never even noticed she was gone.

"Zim? Zim, are you here?"

Gaz poked his doorbell with a stick. Normally what happened next was either a vicious attack by the lawn gnomes or a friendly, if incomprehensible, greeting from Gir. Neither transpired. Gaz tried again, and found the door was unlocked.

She crept into the room, her gaze darting over the dark and silent TV, the Gir-free couch, the scary monkey picture on the wall. "Zim?"

What the hell. She could always make Dib buy her soda now if she had knowledge of the enemy's base. She hurried up the narrow purple steps.

There was only one door, and it was half open. Gaz could hear the sound of faint, rapid breathing. She eased forward until she could see round the door, and what she saw made her go cold all over with a dizzying mix of emotions. Zim lay crumpled on his bed, so pale he was hardly green at all. His hair, sweat-damp, clung to his forehead; his hands were pressed to his chest. She thought fiercely. He was the enemy, according to Dib.

Dib was right, obviously, the green boy was an alien, but Gaz didn't honestly give a crap about that. He was also trying to take over the world, but as far as she could see he was doing a really, really horrible job with that. And she...

No. She wouldn't even think it. Nevertheless she went over to him, knelt down by the bed, smoothed the damp hair away from his face. He was burning up. 

His eyelids fluttered and parted. She had never noticed the bright clear violet of his eyes, and wondered absently why not. She also noticed that they were lenses, the scleral kind that cover the entire eye. He was moaning, trying to say something. 

"....failed......not true Invader........I'm sorry, my Tallest! I'm sorry......"

"Hush," said Gaz softly. "It's all right." Gently she took off the black wig, slipped his scleral lenses from his eyes....she heard him gasp, then, and wondered if she'd hurt him. Without the rather simple disguise, he had brilliant scarlet eyes, pupilless and ruby-clear, and two delicate black antennae arched back over the top of his head. He rolled over abruptly and began to cough, desperately, helplessly. 

Gaz decided.

She ran quickly through what she knew of Zim. He was violently allergic to water, but as far as she could see he had been here for quite a while now without suffering any undue ill effects from the millions of germs he must have encountered. So something must have changed to make Earth germs attack him.

Unless they weren't Earth germs at all.

She collected the pillows that were scattered across the room and piled them up, lifting Zim gently so he was half sitting up in the bed, and pulled the covers up over him. With the change in position, his breathing came more easily, but he was still shivering violently. She was almost sure he was too far gone to recognize her, but she was still expecting him to grab her and start screaming anti-human insults. She almost wished he would; there was something terrible about his helplessness, when he was normally so self-assured. 

Where was his little robot dog thingy, she wondered absently as she tucked him in. Normally Gir would be bouncing mindlessly around downstairs watching the scary monkey show, but she'd seen no sign of his presence. Perhaps Zim had sent him away when this began.

She gently pulled off one of his gloves. The hand underneath was as green as the rest of him, the fingers pointed and strong. Hoping that whatever species he belonged to had blood vessels similar to humans, she brought out another tiny syringe and pierced the skin on his forearm. The fluid she drew up into the syringe was a dark green. Cyanoglobulin, she thought. Like Spock. Heh.

Now all she needed was a fully equipped laboratory.

Professor Membrane regarded the still form of his son, now separated from the world by an isolation chamber. The doctors had explained what little they knew of his illness: it was caused by an unknown pathogen that had protein signatures similar to the coryza viruses. They had their best virologists working on it, they said.

Oh, well, he thought. The world needs my help. I can't achieve anything here.

In a dark room across the city, a single bare lightbulb throws sick shadows over five figures around a table. Bluish smoke curls up from cigars set in overflowing ashtrays; two or three bottles half-full of clear amber brain-death are surrounded by glasses. 

"So who was it topped Vinny, huh?"

"Aaah, dat mook had it comin' to him. Always messin' round where he didn't oughta be. See you an' raise you ten."

"Pass. Ya heard about the Club Miramar job yet?"

"Nah. You want my advice, you stay away from dose creeps. I don' trust em. Dat one with the funny eye, man, he weirds me _out_."

"Gentlemen, please. This is a _poker game_, not some sort of shop-talking session. Kindly concentrate on your game."

"S-sorry, Mister Gir."

"Yeah, sorry, boss. Please don' hurt us?"

"I shall be merciful this time, because I'm winning. I seem to win a great deal when I play poker with you. I wonder why that could be?"

"Uh, dunno, boss. Cause you're so much better at it?"

"I wonder. Or could it be because you're deliberately losing to me? Because if that were the case, I would be forced to terminate you all with extreme prejudice."

"No, please, Mister Gir! Please! Not the lasers!"

"Very well. Shut up and play."

"Yessir!"

Gaz didn't notice the growing pain in her shoulders and back from hunching over the microscopes. Nor did she notice the beeping of one of the myriad consoles that dotted Zim's lab. She was engrossed. It was like nothing she'd ever seen before. Zim's blood itself was fascinating, but the scarlet-stained pathogens she was watching were incredibly bizarre. She knew what most of the human viral strains looked like, and most of the bacteria as well, but this was something quite new. 

Behind her a computer voice cleared its throat. She jumped. The biggest screen was glowing with the words "Incoming Transmission." Presumably from Zim's home planet, wherever that was. She wondered what the aliens would make of her biocontainment suit. The lab had been able to provide all manner of useful things like biocontainment suits once she had asked it nicely. She wasn't afraid of the disease....after all, if she'd been around both Dib and Zim this long and hadn't caught it, she was probably okay.....but she didn't want to contaminate the samples. The screen blinked and showed her a picture of a tall purple-eyed alien regarding her in perplexity. 

"Who are you?" it demanded.

Gaz thought fast. "I'm one of Zim's robot slaves," she said.

"Oh, okay then. Where is he?"

"He's very sick. I've isolated the pathogen responsible but I have no idea what will stop it."

The alien looked around nervously before leaning closer. "I'll help, but don't tell Red about it. He's determined to leave Zim to his fate."

"I promise," said Gaz, thinking what an odd planet Zim must come from. "How do I send you my data?"

"The little purple thingy to your left with the flashy green light on it. Poke the flashy green light." She did, and a small circular pad popped out. "Now put the slides on there and poke the green light again."

In a few minutes the drawer thing reopened to show her the slides. "Have you got it?"

"Yeah," muttered the alien distractedly. "Hold on, I'm asking the mainframe what it knows about this."

Gaz regarded the alien while she waited. He sort of looked like Zim, but his eyes were definitely purple and heavy-lidded, and he was wearing some sort of purple-and-silver armor. Presumably some kind of ruler, she thought. One of his antennae was curling and uncurling itself nervously.

"Ha! Got it! Here's what you do."

Gaz, now beginning to feel the effects of hours of work, hurried up to Zim's bedroom. He was lying quite still, breathing painfully. Gaz knelt by him and took his burning hand in hers; he moaned, opening his eyes, but she was sure he didn't see her. His eyes were hazed and too bright, smoky and feverish. Quickly Gaz pulled back his sleeve and injected the scarlet liquid she'd prepared. As the drug slid into his veins Zim gasped in shock, and immediately began to cough. Gaz withdrew the needle gently. 

"Computer," she said. "Prepare an analgesic and administer it to him." Above her the myriad Doc-Ock arms of the house slid into motion. Gaz hurried down the stairs, one hand clenched around the vial of green serum she'd distilled for Dib. There might be a slight problem getting in to see him, since they'd undoubtedly put him in quarantine, but Gaz figured she'd deal with it when she got to the hospital. 

_Where am I?_

The hatchery. Must be the hatchery. It's so hot in here....

I can't see. I can't breathe! Everything's spinning. 

Earth. I have to be on Earth. My mission was there. I must complete my mission!

What does that matter now? The pain.....

Distantly he felt cool hands on him, a tiny pinprick in his arm, and then a sudden rush of cold that flooded his entire body. He gasped at the shock, and his breath caught painfully in his chest, and he began to cough again. Metal bands were closing on his throat, he couldn't breathe, couldn't stop coughing. Somewhere beyond all that pain he was aware of a low voice saying something, and then another sting of cold in his arm, and gradually the spasm eased and the pain faded into fatigue, and he slept. 

He woke to find daylight streaming into the room. Feeling terribly weak, he turned his head on the pillows and found he wasn't alone in the house.

Gaz.

"What are _you_..." he began, but his cough attacked him again, savagely. She looked up from the Gameslave, and he was surprised to see her eyes were open, and that they were a delicate shade of gold. She sighed, putting the game down and coming over to him. 

"Don't talk. You need rest, Zim." She took something off the bedside table. "Your house says you also need to drink this."

_This is not happening. This is NOT happening. My mission is compromised. There is a human monkey-thing IN MY BASE. It knows my secrets! What am I going to do?_

"If you're worried about me exposing you," said Gaz mildly, still holding out the glass, "you needn't be. I don't give a crap about aliens. I see them all the time. Dib, as you well know, is a freak. Now drink the damn tonic."

Zim drank, trying to understand what she'd just said. "This is foul. What did you put in it?"

"I didn't. Your house did. Look," she said, regarding him with those astonishing golden eyes, "get it through your green head that I am not going to tell anyone about you, or your house, or anything else. Not that anyone ever talks to me anyway."

He swallowed the rest of the stuff. "Ugh. I still don't trust you."

"There's no reason why you should." She took the empty glass away from him. "How are you feeling?"

"Awful," he coughed. It wasn't exactly true; the pain in his chest and head had ebbed to a dull ache, and the dizziness was almost gone, but he still felt terribly weak, and his throat was sore. Gaz seemed to go a little paler as he gasped and coughed.

"What you drank should help. Look, Zim, you need to relax. You're still not well." She looked definitely pained, he thought absently. "Hey. How about this. I'll stay in your house, as your captive, far away from anyone I could tell about you, until you're better. Then you can think about what to do with me."

"I don't trust you not to leave the second I pass out," Zim gasped between coughing fits. 

"Then tell your computer to destroy me if I disobey."

She had a point. "Computer!" he rasped.

"Yes, master?"

"Make sure the Earthinoid remains barred from the outside world until I tell you otherwise. Destroy her utterly if she attempts to escape."

"Yes, master," said the computer tonelessly. Zim closed his eyes.

"Happy now?" said Gaz. He nodded. Something nagged at the edge of his memory. Cool hands, soothing away the pain from his forehead, holding his hand in a firm clasp. He pushed away the image. Gaz stood up, collecting the empty glass and her Gameslave. "I'm going downstairs to watch TV. Not anywhere else. Just downstairs."

"Go," he said, waving a hand in imperious dismissal. He laced his fingers behind his head and regarded the ceiling. He had a lot to think about. 

Zim woke again in the evening. Once again, Gaz was sitting by his bed, only this time her Gameslave was nowhere to be seen. He fixed her with a suspicious red glare.

"Eat," she said. She held out a plate with cherry Pop-Tarts on it. He noticed how tired she looked, how dark the circles were under her eyes. He looked at the Pop-Tarts instead, since for some reason the thought of her fatigue made him uncomfortable.

He hadn't eaten for...how long now? The thought of food should have been an inviting one. "I...can't," he croaked, sinking back on the pillows. Gaz sighed.

"I know, you can't face the thought of food. Just try a corner of one. Computer, have I done anything to these?"

"Negative," said the tinny voice. Zim scowled. He broke off a fragment of Pop-Tart and chewed on it. Amazingly, his nausea receded. He expected to be sick anyway, but broke off another shard and ate that, too. Gaz put the plate on the table, and as she turned back to him he saw that she was smiling.

Zim had never seen her smile before. Not even when she was thwarting Dib. He suddenly felt as if he had never really seen her at all. 

"Better?"

"Yes," he said. _I didn't know humans were like this. Maybe there are others. Maybe I was wrong about them...._

"Good," she said. "I'm going to watch TV again." She left the plate where it was. Thoughtfully, Zim selected a Pop-Tart and ate it, remembering again those cool hands in the heat and the pain.

Downstairs, Gaz was searching for aspirin. She had a killer headache from listening to Gir's mindless babble all day; she had shut him in the lab, inside a large hamster ball, to keep his noise from disturbing Zim, but she felt obligated to check on him every now and then, to make sure he wasn't destroying the place. He liked her. He liked everything else in the world, too, apparently. 

She sighed, finding a bottle marked advil and discovering it to be full of inexplicable green goo. Gir had arrived suddenly after she had returned from the hospital, lugging an enormous briefcase full of money. "Hi purply haired girl! I'm gonna watch TV now!"

"No you're not," she had informed him. "Not here. You can watch TV in the lab."

"Oooh, goody! I love that show!"

She had hurried the little bot down to the lab before he could wake Zim, who was finally in a natural sleep. She had spent the twenty or so hours since then either with Zim or in the lab with Gir, and she was hurting. 

Not just the fatigue and the stress of babysitting an insane robot, either. She couldn't get Zim's eyes out of her mind. That, and the way he'd clung to her hand in delirium, as if he was afraid to let go. Her hand still ached from the strength of his grip. 

Christ. This was ridiculous. 

She slid down to the lab. "Gir?"

"Whee!" He was rolling happily round and round the great open space of the floor, occasionally falling on his head with a loud clank. 

"Gir! It's naptime."

"I love that show!"

She carried him up tucked under her arm, eyes closed in self-disgust. Thank God Dib couldn't see her now. As they reached the kitchen level she clamped her hand over his mouth. "Gir, I want you to listen to me very, very, very carefully. The Master wants you to play a game with me."

"I love games!" he squeaked.

"Sshhhh. I know. This is a special game. It's called "let's be very, very quiet and go to sleep." You have to be good at this one, Gir. If you mess up, the Master told me he's going to cook spinach in your head." Gir shuddered. "Now, are you going to be good at this game?"

"Uh huh," he said, trembling.

"Okay. Let's begin." She lay down on the couch. Gir huddled against her, murmuring something that sounded like 'spinach.' Gaz sighed and put an arm around him, and he clung to her. "Goodnight, Gir."

"'night," he whispered.

Zim drifted out of bizarre dreams to find himself alone. He wondered where Gaz was. Playing her stupid Gameslave, no doubt. "Computer!"

"Yes, master?"

"Where is the Earthinoid?"

"Downstairs, master."

"Give me visual." A screen extended itself from the ceiling. Zim frowned. Gaz lay curled on the couch with Gir, one hand dangling almost to the floor. "Zoom in."

He could see bruises on her hand. Bruises in the shape of fingers. 

"Give me a record of the Earthinoid's movements over the past ten hours."

A schematic of the house appeared, spinning slowly in 3-D. A red dot that marked Gaz's position blinked, showing her first in his room, then down in the lab, then in his room again. She seemed to be keeping watch on something. "She said she was going to watch TV."

"Negative," said the computer. "The Earthinoid female has spent the past ten hours here and in the lab with the G.I.R."

Zim quirked an eyebrow. He wondered how long it had been since she had slept. He realized he hadn't heard Gir's high-pitched nattering all day, either. She must have been keeping him quiet...and Zim knew that was no easy job. 

So Gir wouldn't disturb his master's rest.

And the rest of the time she had been here, with him. 

He ate a Pop-Tart meditatively. _Why is she doing this? What does she stand to gain from it? _If she was serious about keeping his secrets, nothing. If she wasn't, why had she suggested he keep her captive? Why was she even here in the first place? 

He couldn't remember much. Just skool, and the sudden onset of the illness, and reporting to the Tallest. After that it was mostly fever-dreams and pain. How had Gaz come to be in his house in the first place?

He resolved to have a talk with her at the earliest opportunity. But he would wait until she woke up. He still couldn't quite believe she'd worn herself out taking care of him. None of his Invader training had covered anything quite like this. 

In the morning she was there again. Zim could vaguely hear Gir singing a little song about squirrels, but he didn't really mind the noise. He was feeling much better now; most of the pain was gone, and he felt less weak. His throat still hurt, and he had a cough, but in general he was much improved. 

"Here," said Gaz, offering him a bowl of something steaming. "Again, your house is responsible. It says you're recovering quickly but you need particular nutrients."

Zim tasted it. "Better than the last stuff, anyway." He ate, hungrily. His appetite had come back full force after the Pop-Tarts. Gaz rubbed her bruised hand absently. When he had finished, she took the bowl away and made as if to go. "Hey," Zim said. "I need to talk to you."

Gaz sat back down with a thump. "What?"

"Tell me what happened. Why are you here? What's wrong with me?"

Gaz closed her golden eyes for a long moment. "Are you sure you want to know?"

"Of course! It's driving me crazy!"

"Fine," she said, tiredly. "You remember skool, two days ago? How Dib was sick?"

"He's sick too?" Zim grinned unpleasantly. 

"Yeah. Well, anyway, so he went to the nurse, and she took one look at him and called the ambulance. When they got him to the hospital no one could figure out exactly what he had. I managed to get in with Dad and see him, and take a blood sample."

"Waaaait," said Zim. "What do you know about medicine?"

"Jeez, you think that Gameslave is the only thing I do? Don't answer that. So I had a vague idea it might have something to do with you. The illness, I mean. There are so many books about alien germs destroying mankind, I figured it might be worth a shot. So I came here. Gir was out, the door was open. I snuck inside and found you lying here collapsed. You were so ill, Zim..." She paused, took a deep breath. "I realized you and Dib were suffering from the same thing, more or less. I took a sample of your blood and, uh, kind of asked the world in general where I might find a fully equipped laboratory. Your house heard me." She tucked her hair behind her ears, and again Zim saw the dark bruises, the print of a hand. "Convenient. So I had a look at your blood, both of you guys, and found there was this bizarre pathogen that didn't look entirely human but which certainly had human characteristics. I realized you'd swapped germs somehow, you and Dib."

"I did what?"

"I don't know. Maybe last time you guys got in a punching match or something you got some of his germs and he got some of yours. Obviously, the normal common cold for humans is not life-threatening, and I assume your species has something similar. However, if you attack a alien immune system with a full-blown case of the human common cold, the alien is, well...."

"I see," said Zim. "Which is why you didn't get it from me."

"I've already had this one from Dib, the jerk. Anyway, I was trying to figure out a way to reverse it when someone called you. Some guy with purple eyes."

Zim had a coughing fit. "Mother of Irk!" he choked. "The Almighty Tallest called and found a human in my lab?"

"Relax," she said, absently pushing him back down to the pillows. "I was wearing a biocontainment suit. I told him I was a robot slave. He bought it."

Zim subsided, gasping. "Ow," he groaned. "My throat..."

Gaz went paler again. Zim wondered about that. "Here," she said. Her voice sounded softer, as if she were concerned. He took the proffered glass and drank, closing his eyes as coldness numbed his throat. "He was very helpful, actually. He wanted to cure you. I sent him what I had, and he ran it through his computer. Apparently your species does a lot of invading, and they sometimes come across situations like this. All I had to do was extract antibodies to your germs from your blood, and Dib's germs from Dib's blood, and match antibody to germs. It took a little longer than that, mostly because I had to match chemical content and salinity and a lot of other crap, but eventually I had a cure for you and a cure for Dib. I gave you the shot and, uh, broke into the hospital to give Dib his. Then I came back here."

"Why?" Zim asked. 

She didn't answer immediately. "I suppose I wanted to see if it was going to work."

"Then why didn't you stay with Dib? He _is_ your brother."

"I know that," she said acidly. "As I was saying, I wanted to see if it was going to work on _you_. There was something about you as you were lying there so ill....I needed to know if you would recover."

Zim pondered this. Gaz's eyes were screwed shut again, as they normally were. He wanted, suddenly, to see those golden eyes again. He wanted to see that _smile_ again. 

"Thank you," he said, simply. "And thank you for staying. I...didn't know humans did that."

"Did what?"

"Um," he said brilliantly. "Not....do what they....normally do....so as to help someone else."

There it was, the smile again, that smile. "It's called caring, Zim. At least I think it is. I've not experienced much of it myself. And you're welcome. I stayed because I wanted to."

Zim wanted to say something, but his cough wouldn't let him. He bent over, hacking into his fist, furious at his body for misbehaving. Gaz watched for a moment before giving up and putting her arm around his shaking shoulders, rubbing his back. The spasm began to ease, and she let him lie back against the pillows. Slowly he opened his eyes and looked at her.

"I'm sorry, Zim," she said. "I know you hate human contact."

Oh, Mother of Irk, there was _so_ much he wanted to say. He settled for shaking his head and smiling weakly. "It's okay, Gaz," he croaked. "I didn't mind."

Oh, that smile. That smile alone made him feel so much better. He had just about given up on logic by now.

"What are you going to do about me and the secrets and the destruction and stuff?" she asked, suddenly.

"I don't know," he retorted. "Are you going to expose me?"

She pulled her hair out of her eyes and regarded him with a steady golden gaze. "Zim, I have stayed with you for two days straight. I have slept all of four hours in that time. I have dealt with Gir for you. I have lied to the rulers of your planet. I have, in all probability, saved your life. I have nursed you back to some semblance of health. And now you think I'm going to run out of here and call Mysterious Mysteries to report an alien with a bad cough living in my skool district? No, Zim. I am not going to expose you."

She let the hair fall back, hiding her face. Her shoulders trembled. Zim sat up, the impact of her words ringing in his skull. "Gaz," he said. 

"What?" Now her voice was low and rough.

"Gaz, I'm sorry. I know I owe you. I can hardly understand why you did all this for me, but I am grateful. And I trust you."

Slowly she parted the wings of hair. Tears stood in those eyes. Zim found he really, really didn't like that. He did the only thing he could think of to do. He put his arms around her and held her tight. 

Gaz gasped. She could hear the beating of his heart...a strange rhythm, a heart unlike any she'd ever heard of. She felt him beginning to draw back, and hugged him tighter for a moment.

"Thank you, Zim," she said into his shoulder.

"For what?"

"I don't know. But thank you."

A watery sun once again glinted from puddles in the skoolyard. Zim leant against a fence and watched the kids playing with amused disdain. Dib elbowed Gaz. "Look at him! He's got to be plotting something!"

"Quit bugging me, Dib," she growled. 

"But look at him! He's so obviously an alien!"

"Whatever," said Gaz. "I don't care whether or not he's an alien. You're an alien, Dib. You've definitely got a bit of alien in you."

"Well, you must truly know your enemy to hunt them down!"

Gaz frowned more fiercely so as not to snicker. Zim's blood ran in Dib's veins now. The irony was killing her. Of course, Zim now had a tiny smidgen of human blood. She thought it was sort of fitting. "Yeah," she said. "You have to know your enemy, all right."


End file.
